This discussion paper synthesises evidence on the role that nature-based solutions (NBS) could play in mitigating flood hazard risk in Malawi.
Nature-based solutions recognise the fundamental role ecosystems play in addressing the challenges associated with improving degraded ecosystems, and ‘working with nature’ to enhance water security, manage extreme weather events and mitigate and/or adapt to the impacts of climate change. This discussion paper looks at the kinds of NBS that help mitigate flood hazards, the relative resilience dividends of investing in NBS compared with ‘grey’ infrastructure, and the approaches/methods that can be used to evaluate NBS options for flood mitigation.
The paper finds that three key features of NBS need to be considered when appraising them as infrastructure options for flood mitigation, whether in isolation, or more likely in combination with grey infrastructure - so-called hybrid solutions.
1. NBS effects ripple through catchments, generating benefits, and costs, beyond their primary intention
2. water-related benefits are often uncertain
3. valuation of specific costs and benefits is difficult, not least because isolating and attributing cause and effect is so difficult.
Based on this, the paper recommends an analytical framework for NBS for flood mitigation.